Typically, image processing is based on the “appearance” of an object recorded on imaging elements by capturing an image. The appearance of the object is obtained by the imaging elements receiving light from the light source after being reflected at the object surface. Currently however, image processing also includes the processing of augmented reality images in which computer-generated graphics images, being virtual objects, are laid over a real image.
In such applications it is necessary to estimate the light source characteristics and reflectance properties of the object surfaces of a scene to be able to properly predict and apply expected reflections and shadows in a scene. It is also possible to modify the lighting positions and reflectance properties once the light source characteristics are known.
In current techniques for estimating light source characteristics and reflectance properties of a scene, a captured image of the light source, i.e., a light source image, is needed. In some instances such an image can be obtained in conjunction with the imaging of a scene and in other instances a separate image of the light source must be captured. In either case, it is essential to capture an image of the light source for estimating light source characteristics and reflectance properties of a scene.
However, what can be very useful is to be able to estimate light source characteristics and reflectance properties of a scene without the need to capture an image of the light source(s).